Though not illustrated, a conventional substrate storage container includes a container body for accommodating a plurality of semiconductor wafers, a lid body that opens and closes the front of this container body and a locking mechanism for locking the lid body that closes the front of the container body, and is used when transporting semiconductor wafers to semiconductor manufacturing factories (see Patent Documents 1, 2 and 3).
The container body is molded in the form of a front-open box having such a size as to be able to hold semiconductor wafers of, for example 300 mm or larder in diameter, accommodated in alignment while a bottom plate is attached to the baseplate of the container body. A plurality of positioning tools that fit the positioning pins on the table of lid opening/closing equipment to do positioning are attached to either the baseplate or the bottom plate.
The lid body is composed of a lid main body having an approximately dish-like section and detachably fitted to the front of the container body and a cover plate that covers the open front of the lid main body. A locking mechanism is arranged between these lid main body and cover plate so as to be opened and closed automatically by lid opening/closing equipment. The cover plate is formed of a plate that is sized so as to correspond to the front of the lid main body while operation holes for the locking mechanism are formed in the center on either side of the cover plate.
The locking mechanism is formed of a pair of rotating operation portions that are pivotally supported by the lid main body of the lid body and rotationally operated from the outside and a plurality of latch bars that are projected from and retracted into the peripheral wall of the lid main body to thereby come into and out of contact with the inner periphery in the front of the container body. Each rotating operation portion is provided in the form of a disk having, for example, a pair of curved slots in its peripheral part, arranged opposing the operation hole of the cover plate, and rotated from the outside by means of an operation key of lid opening/closing equipment that is inserted through the operation hole.
In the thus configured substrate storage container, when the lid body is fitted to the open front of the container body and locked, the lid body is held by suction by means of lid opening/closing equipment so that the suction-held lid body is pressed to the open front of the container body and fitted shallowly. When the lid body has been shallowly fitted, the operation keys of lid opening/closing equipment are inserted into the operation holes of the cover plate, and the rotating operation portions of the locking mechanism are rotated so that a plurality of latch bars of the locking mechanism slide, respectively. As a result, the lid body is brought into tightly contact with the inner periphery in the front of container body, whereby the lid body perfectly fits to the front of the container body and strongly locked.